The official Addons for Invoicing, extend the core plugin to get the functionality your business needs.
PDF Invoices
This Invoicing plugin automatically attaches a PDF invoice to the invoice emails sent out to the customers. Option to display download PDF button in invoice history. Options to attach PDF in emails sent to the customers. Option to display message in header and footer of PDF invoice.
Gravity Forms
Create a gravity form with the required mapping fields and select form type invoice/quote from the Invoicing tab and use shortcode to display form. Create WPI Gravity Form Feeds from the gravity form form settings->WPI Gravity Form. Select type for invoice or quote and map the form fields with invoicing fields. Email is the required
AffiliateWP Integration
Integrate with AffiliateWP and start rewarding whoever send traffic to your website by paying them a commision whenver one of his referrals converts into a sale.
Contact form 7
Create a contact form with the required mapping fields and select form type invoice/quote from the Invoicing tab and use shortcode to display form. When user request quote or invoice from contact form 7, admin can add items to the quote or invoice later and send it to the user for payments.
Ninja forms
Create a ninja form with a template called Create Invoice/Quote with required mapping fields. Go to Emails and Actions tab of the form and enable Create Invoice or Quote action. Click on the settings icon to map the fields and select type Invoice or Quote you want to create and then publish the form.
Quotes
Quotes add-on for the WordPress Invoicing plugin = Allows you to create quotes, send them to clients and convert them to Invoices when accepted by the customer. This plugin requires to install the [Invoicing plugin](https://wordpress.org/plugins/invoicing/) = Features = * Create quotes and estimates to send to your clients. * Quotes can be turned into
